The operation of a mechanical device for the composition and reading of a music score is based on the concepts of: rhythmic pulsation, also named beat; the names of the notes according to their respective duration values, the value and number of beats.
The presence of a constant rhythmic pulsation, which divides time into equal parts so as to provide a reference “grid” for the reader or player, is necessary to read, interpret and play a score. The pulsation speed is expressed in bpm (beats per minute) and hypothetically may vary from 1 bpm to +infinite bpm. Commonly, bpm from 30 to 300 are adopted.
Each note corresponds to a sound and various note values exist to determine their duration in time. The whole note is the longest note, to which the value of 1/1 (one whole) is attributed; the values of the other notes are obtained by dividing always by 2 (to obtain 1/64 or 1/128, for example).
In order to determine the actual duration of a note in time, a value that is included in the note values must be attributed to the beats (rhythmic pulsations) so as to establish a concrete relationship.
Example: a pulsation of 60 bpm is given. It is established that each pulsation (beat) equals 1/4 (one quarter note). In such a case, a whole note (4/4 note) will last for 4 seconds. By increasing the pulsation to 120 bpm, but maintaining a value of 1/4, the same whole note (4/4 note) will last exactly half the time, i.e. 2 seconds.
By maintaining instead the pulsation at 120 bpm, but changing the value from 1/4 to 1/8 (one eighth note) the same whole note (4/4 note) will last for 4 seconds again.
After having established the value, groups of beats must be created to allow to divide the score into equal segments. Such segments are called bars or measures and allow to read the part from a given point or to repeat some parts by means of the so-called “ritornello” signs.
The tempo type according to which the part will be written is determined at the beginning of the score by means of a numeric fraction. This means establishing how many beats there must be within each measure and what their value will be.
Example: fraction 3/4 at the beginning of the part means that within each bar there will be 3 beats in each bar, having a value of 1/4 each. Thus, the numerator indicates the number of beats and the denominator determines the value thereof. Consequently, there are no numeric limits for the numerator, but such limits exist instead for the denominator, which must indicate a value included in the note values (4 means 1/4, 8 means 1/8 etc.).
Furthermore, the sum of the note values and of the pauses contained in the same bar must correspond to the value expressed at the beginning of the score.
Teaching devices of the mechanical type, formed by rollers or faceted disks, which turn independently to provide information on the combinations of musical scores to be played, are known in the prior art.
For example, according to U.S. Pat. No. 6,031,172 a music teaching device comprises a number of rings positioned so as to have an independent movement by turning on a base element. According to the shape of the base element, the reference rings are either coaxial cylindrical sleeves or concentric rings. The outer surface of each ring is divided into segments which can be identified by means of predetermined colors. Each segment shows signs referring to a note of the chromatic scale. The device works so that, when the various ring segments are aligned according to the same color, the corresponding segments of each next ring represent the notes of a non-chromatic scale.
In each of the prior art, it is the object of the present invention to make a music teaching device which can further facilitate the study and learning of a musical instrument by combining a sequence of music fragments to compose a plurality of musical pieces, in particular rhythmic pieces, in more stable, easily changeable and repetitive manner.